Yamaha YZF-R125 Owners Manual: Ignition circuit cut-off system

Yamaha YZF-R125 Owners Manual / Instrument and control functions / Ignition circuit cut-off system

The ignition circuit cut-off system (comprising the sidestand switch, clutch switch and neutral switch) has the following functions.

It prevents starting when the transmission is in gear and the sidestand is up, but the clutch lever is not pulled.
It prevents starting when the transmission is in gear and the clutch lever is pulled, but the sidestand is still down.
It cuts the running engine when the transmission is in gear and the sidestand is moved down.

Periodically check the operation of the ignition circuit cut-off system according to the following procedure.

WARNING
If a malfunction is noted, have a Yamaha dealer check the system before riding.

Sidestand

The sidestand is located on the left side of the frame. Raise the sidestand or lower it with your foot while holding the vehicle upright. TIP The built-in sidestand switch is part of the ign ...

For your safety - pre-operation checks

Inspect your vehicle each time you use it to make sure the vehicle is in safe operating condition. Always follow the inspection and maintenance procedures and schedules described in the Owner's Ma ...

Other materials:

Separating the crankcase
1. Remove: Crankcase bolts NOTE: Loosen each bolt 1/4 of a turn at a time, in stages and in the proper sequence as shown. A. Right crankcase B. Left crankcase 2. Turn: Shift drum segment NOTE: Turn the shift drum segment "1" to the position shown in the illustration. In this ...

Throttle position sensor
1. Check: Throttle position sensor a. Connect the digital circuit tester to the terminals of the throttle body sensor assembly coupler as shown. Positive tester probe → gray/red terminal "1" Negative tester probe → gray/black terminal "2" b. Measure the throttle pos ...

Checking the connections
Check the leads, couplers, and connectors for stains, rust, moisture, etc. 1. Disconnect: Lead Coupler Connector 2. Check: Lead Coupler Connector Moisture → Dry with an air blower. Rust/stains → Connect and disconnect several times. 3. Check: All co ...